We propose to study three brain areas known as the habenula, ventral midbrain and anterior raphe areas. The habenula appears to send positive and negative emotional signals to both ventral midbrain and anterior raphe areas. These two areas contain neurons that make brain chemicals called dopamine and serotonin, whose signals can affect many brain structures involved in motivation and learning. Indeed, dysregulation of both dopamine and serotonin signals has been linked to psychiatric disorders including drug addiction and mood disorders. We will use optogenetics (see the 1st paragraph of this section) to selectively stimulate and inhibit habenular signals affecting the ventral midbrain, and anterior raphe areas, to determine how they play roles in controlling dopamine, serotonin and motivated behaviors in mice. Currently, we are still at the stage of setting up equipment and refining procedures. We should be able to begin collecting data on the proposed questions in coming months.